Cosmology is even worse. Cosmology is little more than an ongoing flame war. For example, is is dogma that all the galaxies are moving away from each other... Well except for hundreds of galaxies in the local group which are headed for a collision somewhere in the great attractor which is the most massive thing yet observed.... but there is nothing there...
Until 7-8 years ago, it was astronomy/cosmology dogma that the galaxies were slowing down... That is until a bunch of observations were made that suggest they are actually speeding up... In another case, which may just be a fluke, but it may not, there is a huge gaping hole in the data in the Hubble Ultra deep field. It goes on and on like this, as it should.
There are no answers here only best guesses, that is why it is still an interesting area of amature research. The mystery of it all. Very little of astronomy or cosmology dogma even amounts to theory status.
The unknowns vastly outweight the knowns in astronomy and cosmology. This is why amature astronomers are still doing good science, and making discoveries. If you want to beleive in Planet X or whatever, dont let anyone tell you that it doesnt exist. Better yet, start building your telescope and be the first to find it. With diligance I bet you can find a previously undiscovered comet and get it named after you. If you find Planet X, hats off dude, you are gonna be right up there with Newton, Einstein, and Armstrong the the history books, as the guy who caused a total rethink of the science.